I can remember the day I first decided to be Gay. I was 15 and on my way home from school. Before that afternoon, I'd always seen sex as something I did rather than something I was; a behaviour rather than an identity. I'd had sex with a few boys and a girl without even suspecting it could define me. But on that afternoon, I thought it would be fun to play with a new identity – and that's when I chose to be Gay.

I remember seeing a guy buying a copy of Gay Times magazine and he looked like me but happier. It may sound flippant but that's when I first thought about being Gay as an identity (the capital letter isn't an accident); a semi-conscious process that really made a mark on me in that moment. It was like seeing my reflection in a different mirror.

I'd grown up in local authority care until that point and been alone for a lot of my life. I'd often been shut in my room for very long periods with no books or music. The positive side of that is it meant I did more than my fair share of self-reflection and got to know myself quite well. I thought a lot about doing v being. Who was I? Did my behaviour create me? Who was I beyond my behaviour?

I knew that some guys played football and became Footballers, and some guys just played football. Some guys slept with other guys and became Gay, and some guys just slept with other guys.

I knew that the roles I played – roles like "son", "brother", "Londoner", etc – gave form to my thoughts and those created my experience of myself. I decided to reinvent myself by playing the Gay role wholeheartedly.

Coming out at school the next day was simple: I confided in someone I knew would tell everyone else. The reaction was swift and electric. The next break time, a huge crowd of kids surrounded me and bombarded me with questions and insults. The insults excited me more than the questions and it felt amazing actually. People couldn't see me as a person anymore; they only saw a Gay. None of their insults were personal; they were all about Gays. I felt so shielded and safe. Even when some boys smashed a glass bottle over my head, I felt untouchable.

I knew I was playing a role but it didn't always feel that way. I became friends with the actor Ian McKellen for a while and it always seemed funny to me when he'd come off stage and became Ian again, even while he was still in the makeup and costume of his character. I asked him how he knew who he was and we talked about that.

Once I'd turned 16, I lodged a case in the European court of human rights and argued that the United Kingdom was prejudiced against me and other Gay teenagers. Having sex with another man was illegal for me when I was 16 while having sex with a woman was fine. The age of consent was 18 for men with men; 16 for men with women. I joined a campaign group and was on the cover of Gay Times, featured on television and invited to meet politicians.

I also toured universities, giving talks and sharing my experiences. The students were a few years older than me but their lives were unfolding too. It felt like a stealth mission because by day I would be studying for A Levels, or at least pretending to, and then in the evenings I would do my real work of affirming our right to create our lives and our identities however we chose. Universities are magical places — full of people reinventing themselves.

It was funny: my lawyers for the European court case kept telling me that we'd win and I kept thinking 'so what?'. It didn't cross my mind that we wouldn't win but it wasn't about that. I didn't want to win heads with legal and intellectual arguments, I wanted to win hearts and have people accept us. By us, I mean me really. I wanted people to accept me – but I wasn't ready to ask for that. I thought identifying myself as Gay and asking people to accept Gays was a first step — and I thought it would help others too.

It was difficult though. I remember one day we were fundraising for the campaign and I was dancing with Robbie Williams and other celebrities at the Royal Albert Hall. We sang We Are Family and the atmosphere in the Hall was beautiful. I didn't feel part of any family though. I'm not sure many of us did. We were so caught up with our Gay masks, and you can't love a mask.

I got what I really wanted in the form of Chas, a beautiful young journalist who phoned and asked to write about me for a Gay magazine called Attitude. I knew instantly that we'd spend the rest of our lives together. It felt so right and so perfect and I loved him with my whole heart. Somehow he loved me too, and I remember loving myself for the first time too.

Chas saw beyond my mask. Meeting him was the first time I felt truly seen. We loved each other immediately, moved in together within weeks and I gave up campaigning to make my life about learning to do for others what Chas had done for me. I studied psychology and began a new path, learning to see people as they truly are.

Fourteen years later, I don't think I'm Gay any more; I just know I'm in love with a wonderful man. And that is why I support same-sex marriage, because love transcends everything and it doesn't matter who you love as long as you love.

I want future generations to take it for granted that their love is as real and genuine as anyone else's, whoever it is they love. Nobody should have to soul-search and wonder why their love is considered less worthwhile than other people's. Nobody should question if loving someone makes them sick or evil. And nobody should be afraid to love, unable to even imagine themselves in love.

Matthew Todd wrote in the Guardian about how shame still cuts deep in many people, including many who seem happy and successful. I think sometimes it's the people who talk most about pride who are the most gutted by shame. I won't duplicate Matthew's excellent article but I will add this: I think shame is at the root of our current financial crisis and all the problems in our country. Shame affects everyone who holds back the whole truth of who they are because they are afraid of rejection, and that means almost all people. Shame eats away at us and makes us less creative, less productive and less willing to contribute to society. Shame makes us independent rather than collaborative. It makes us pessimistic rather than optimistic. It makes us care less about our health and it leads to addictions, anxiety and antisocial behaviour. The cost of shame is immense.

Treating each other with dignity is as simple as honouring what's underneath our individual masks. We're all human beings and all equally worthwhile. The ripple will be infinite when all people are respected and all love is celebrated the same way.

• This article was originally appeared on chrismorris.com and is republished here with permission